This invention relates to an imaging apparatus which produces a monochromatic image of a selected band of wavelengths from a polychromatic source image, and more particularly, to such an apparatus wherein a pair of monochromators are utilized therein.
In the prior art, there are known two types of double monochromators, one of which has been used for imaging purposes. In that instrument, it was only possible to reproduce an image at only one wavelength, to any degree, and not over a selected band of wavelengths. For example, for use in human spectroscopy, an isolated spectral line was possible of isolation and viewing. However, in the art, there is no apparatus which can by simple manipulation, view a polychromatic source image, as well as a monochromatic image of any selected wavelength or band of wavelengths, with faithful reproduction of the source image.
It has been known to use a double monochromator as a scanning spectrometer wherein an entrance slit, collimating mirror, grating, camera mirror, intermediate slit, second collimating mirror, second grating, second focusing mirror and exit slit were employed. In this prior spectrometer, the slits were extremely narrow so as to produce a precise one dimensional resolution of the spectral lines. However, there has not yet been produced a monochromatic imaging device wherein an accurate reproduction of the source image was produced and of a selected single wavelength or band of wavelengths.